Surface area of a sphere (3D solid's name for ball shaped object) is given by
[tex]SA = 4 \pi r^{2} [/tex]
We do not know the radius of the sphere but we can work it out from the circumference [tex]8 \pi [/tex]
[tex]Circumference = 2 \pi r[/tex]
[tex]8 \pi =2 \pi r[/tex]
[tex]r= \frac{8 \pi }{4 \pi }=2 [/tex]
then
[tex]SA=4 \pi (2)^{2} =16 \pi [/tex]
